Can you explain the process of synaptic transmission?

A synapse is the junction between a neurone and the next cell. At the synapse there is both a presynaptic neurone, with vesicles containing neurotransmitters (chemical messengers) and a post synaptic neuorone/cell, this has a membrane occupied by receptors specific for the neurotransmitters stored in the presynpatic neurone. When an action potential stimulates the PreS neurone, vesicles fuse with the PreS membrane - releasing neurotransmitters into the synaptic cleft ( this is the tiny gap between neurones). These neurotransmitters bind the receptors on the post synaptic membrane, here sodium channels open and an influx of sodium causes a depolarisation of the post synaptic cell. Thus, a transduction from electrical to chemical to electrical energy occurs – transmitting the message across the synapse (draw diagram).

JD

Related Biology A Level answers

All answers ▸

How are action potentials propagated across cholinergic synapses?


Briefly describe the main differences between fast and slow twitch muscles and how does this relate to their specific functions.


What is the mitochondria and what is its role within the cell?


How may allopatric and sympatric speciation be distinguished? (4 marks)